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Two different 2-digit numbers are randomly chosen and multiplied together. What is the probability that the resulting product is even?

MathCuber  Aug 11, 2018
 #1
avatar+91160 
+1

There are 90  2 digit  numbers.....the total possible pairs   = C(90,2)

 

An odd can only occur if we multiply  any two odds together.....the number of possible pairs  = C(45,2)

 

So....the probability  of an even product  is......  

 

1  - probability of an odd product  =

 

1  - C(45,2)/C(90,2)  =

 

67/89 ≈ 75.3%

 

EDIT to correct a silly error pointed out by Guest...!!!!

 

 

cool cool cool

CPhill  Aug 11, 2018
edited by CPhill  Aug 11, 2018
edited by CPhill  Aug 11, 2018
edited by CPhill  Aug 11, 2018
 #2
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+1

CPhill: Don't you have only: 99 - 10 + 1 =90 - 2-digit numbers??

Guest Aug 11, 2018
 #3
avatar+91160 
0

Yep...my bad...see edit....

 

 

cool cool cool

CPhill  Aug 11, 2018

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